Radon is a naturally occurring radioactive gas that seeps from soil into homes, posing health risks with long-term exposure. ICF construction's airtight foundation systems make radon mitigation straightforward and effective.
Understanding Radon Risk
Radon is the second leading cause of lung cancer after smoking. It's produced by the natural decay of uranium in soil and rock, seeping up through foundations and accumulating in homes. Parts of Central Texas have elevated radon potential due to our geology. The EPA recommends testing all homes and mitigating if levels exceed 4 pCi/L.
How Radon Enters Homes
Radon enters through any opening between the home and soil: cracks in slabs, gaps around plumbing penetrations, sump pits, and the natural porosity of concrete itself. Conventional construction has numerous potential entry points. The negative pressure created by HVAC systems and the stack effect can actively draw radon-laden air into homes.
ICF's Natural Advantages
ICF construction addresses radon entry points more effectively than conventional building. The sealed, airtight construction that makes ICF energy efficient also limits radon pathways. When combined with proper sub-slab preparation, ICF homes can achieve very low radon levels.
Radon-Resistant New Construction
EPA guidelines for Radon-Resistant New Construction (RRNC) are straightforward to implement in ICF homes. Key elements include a gas-permeable layer (typically gravel) beneath the slab, a polyethylene vapor barrier over the gravel, sealing of all slab penetrations, a 3-4 inch PVC vent pipe from sub-slab to roof, and electrical rough-in for potential fan installation.
These measures cost relatively little during construction but are expensive to retrofit. We include radon-resistant features as standard practice in all ICF homes.
Active vs. Passive Systems
Passive radon systems rely on natural air movement and the stack effect to vent radon from beneath the slab. Active systems add a fan to the vent pipe for positive extraction. In ICF homes with their naturally tight construction, passive systems often prove sufficient. However, we rough-in for fan installation so upgrading to active mitigation is simple if testing indicates need.
Testing Your New Home
We recommend testing all new homes for radon after occupancy, even with radon-resistant construction. Short-term tests (2-7 days) provide initial screening; long-term tests (90+ days) give more accurate annual averages. If levels exceed EPA guidelines, activating the passive system with a fan typically resolves the issue.
Peace of Mind
Building radon resistance into your ICF home costs little but provides lasting protection. Combined with ICF's other health benefits—filtered air, controlled humidity, no mold—you're creating a home that actively supports your family's wellbeing.
Build a Healthy Home
Contact Austin Touchstone Builders to discuss radon-resistant ICF construction.
Schedule ConsultationOr call us: 512-428-6224